title: Self-assembled peptide beads used as a template for ordered gold nanoparticle superstructures.
abstract: Using peptide-based materials to tailor self-assembled, nano-scaled hybrid materials with potentially high biocompatibility/biodegradability is gaining importance in developing a broad range of new applications, in areas such as diagnostics and medicine. Here, we investigated how the self-assembly ability of amphiphilic peptides can be used to create organized inorganic materials, i.e. gold nanoparticles. A bead-forming, purely peptidic amphiphile Ac-[K(Ac)]3-[W-l]3-W-NH2, containing acetylated (Ac) l-lysine (K), l-tryptophan (W) and d-leucine (l), was C-terminally modified with a l-cysteine (C) and linked to gold nanoparticles. Subsequent peptide-driven self-assembly of the peptide-coated gold nanoparticles with increasing water content led to controlled aggregation of the gold-core micelles, forming composite peptide-gold superstructures. The individual gold nanoparticles did not agglomerate but were separated from each other by a peptide film within the composite material, as revealed by electron microscopy studies. Structural investigation on 2D template-stripped gold demonstrated the ability of the peptides to form self-assembled monolayers. Structural elements of β-turns and weak hydrogen bonding of the hydrophobic moiety of the peptide were evident, thereby suggesting that the secondary structure remains intact.
authors.affiliation: Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland. Electronic address: dirk.de_bruyn@gmx.net.
authors.forename: Dirk
authors.initials: D
authors.lastname: de Bruyn Ouboter
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Schuster
authors.forename: Severin J
authors.initials: SJ
authors.lastname: Sigg
authors.forename: Wolfgang P
authors.initials: WP
authors.lastname: Meier
mesh_terms: D006046:Gold / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008823:Micelles; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D053761:Nanocomposites / Q000737:chemistry / Q000648:ultrastructure; D010316:Particle Size; D010455:Peptides / Q000737:chemistry*; D055503:Protein Multimerization; D013501:Surface-Active Agents / Q000737:chemistry
chemical_list: D008823:Micelles; D010455:Peptides; D013501:Surface-Active Agents; D006046:Gold
keywords: Amphiphilic peptides; Gold nanoparticles; Hierarchical hybrid material; Nanotechnology; Self-assembly